Electrical reproducer for phonograph records



Dec; 10, 1929. L. D. :HARRIS ,739,228

ELECTRICAL REPR ODUGER FORPHONOGRAPH RECORDS Original F fi ed June 121926 2 Sheets-Sheet l Dec. 10, 1929. 1.. D. HARRIS I ELECTRICALREPRODUCER FOR PHON OGRAPH RECORDS Original Filed June 12, 1926 2Sheets-Sheer 2 I Patented Dec. 10, 1929 v UNITED STATES LELAND D.HARRIS, OI SALT LAKE CITY, UTAH ELECTRICAL .REPRODUCER FOR PHONOGRAPHRECOBDS Application filed June 12, 1926, Serial j This invention relatesto and has for one of itsv objects the provision of an electricalreproducer and amplifier for phonograph records which will eliminate allrasping and other'mechanical noises, which will reproduce the record. inthe clear natural tones used in the making of the same, and which willpermit the tone and volume of the music to be varied at the will of theoperator;

With theforegoing and other objects in View, the'na ture of which willbecome apparent as the description proceeds, the invention consists ofthe novel construction, combination and arrangement of parts hereinafterfully describedand claimed, and illustrated in the accompanyingdrawings,

wherein:

Figure 1 is a view partly in elevation and partly in vertical section ofthe electric generator and modulator of the device,

, Figure 2 is an elevational view looking at the electric generator fromthe side opposite that seen in Figure 1, p

. -Figure 3 is a'sectional view taken on the plane indicated by the line3-3 of Figure 2, Figure 4 is a detail elevational view of the armatureand coil of the electric generator, Figure 5'is a sectional view takenon the plane. indicated by the line 55 of Figure 4,

Figure 6 is a detail perspective view of the armature and supportingframe therefor,

Figure 7 is a detail perspective view of the pole pieces of the electricgenerator,

Figure 8 is a detail perspective view oi the core of the coil, and

Figure 9 is a diagrammatic view of the electric generator, modulator andamplifier. Corresponding and like parts are referred to in the followingdescription, and vdesignated in the several views of the accompanyingdrawings, by similar reference characters.

The electric generator comprises semi-circular permanent magnets 1 and 2which are arranged with their like poles opposite each other and aresecured in any suitable manner within a case 3. Pole pieces 4 and 5which extend diametrically of the magnets 1 and '2, have their outerends secured as at 6 to the ends of the magnets. These ends of the poleNo. 115,524,. Renewed April 12, 1228.

pieces 4-and 5 are notched to provide air gaps 7, and the inner endsthereof are of substantially U-form, as shown at 4 and 5", and arrangedwithin the magnets 1 and 2. The ends of the magnets l and 2 arerelatively spaced. The polepieces 4 and 5 are posi-. tioned at one sideof the magnets 1 and 2, and the air gaps 7 of the pole pieces occupy aposition between the ends of the magnets. The U-shaped ends 4 and 5 ofthe pole pieces 4 and 5 are arranged at right angles to the plane of thepole pieces to permit them to extend into the magnets 1 and 2 as stated.A coil 8 is arranged withintheendsl and 5 of the pole pieces 4 and 5,and is mounted on A a spool which consists of a hollow metallic core 9and sides 10 of bakelite or other suitable insulating material. The core9 is provided with lugs 11 which contact with the outer it'ac es of thesides 10 to hold it, the sides and the coil 8 together. An open frame 12carried by the core 9 and adapted to be" inserted therein from an endther'eof, is provided with shoulders 13 to limit the extent .of itsinsertion into the core. An armature 14 is, rockably supported withinthe frame '12 by a spindle 15, and is provided with an Y nected'tothelug 16 of the armature 14 by a link 23. The terminals 8 of the core 8are secured to binding posts 24 carried py the 'pole pieces 4 and 5. Theends 4 and 5 of the pole pieces 4 and 5 contact with the frame 12, tohold it against casual movement The thickness of the frame 12 is greaterthan the corresponding dimension of the armature 14 is order to permitthe latter to vi brate ireelyjin unison with the stylus 18 as the lattertravels over the phonograph record 21.

The case 3 is carried by a hollow arm 25 which is adjustable lengthwisein a sleeve 26 r'ockably supported as at 27 on a post 28. A set screw29-permits the arm 25 to be secore 33, a primary win ing cured inadjusted position. with res ect to the sleeve 26. The post 28 is swively, c0n-- nected as at 30 to a case 31 in which is mounted a transformer32 com rising a laminated 34 and a SEC,- ondary winding 35. Leads 36extending from the binding posts 24 and through the arm 25, areconnected to the terminals of the primary winding 34, and leads 37 notending from the secondary winding 35, are connected to binding posts 38carried by the case 31. V

The secondary winding 35 of the trans former 32 is. connected to theamplifier 39 shown, diagrammatically in Figure 9. This amplifiercomprises vacuum tubes 41, 42 and 43, high ratio transformers 44 and 45,an A battery 46, a B battery 47, adjustable resistance 48, filtercondensers 49 and 50, a high resistance by pass coil 51, and adjustablegrid resistance 52.- The secondary 35 of the transformer 32 hasconnected thereto a plug 53 which is ada ted to be inserted in the inputsocket 54 o the am lifier 39. The amplifier 39 is also provi ed with anoutput s0cke t'55 to receive a plug connected to a loud speaker, horn,telephone receiver or the like.

From the ioregoing description, taken in connection with t e accompanyindrawin s, it will be understood to those skilled in t e art to whichthis invention relates, that the vibration of the armature 14 by and asthe result of the movement imparted to the stylus 18 by the phonogra hrecord 21, 'will generate electrical impu ses of varying intensity inthe coil 8, that these impulses are am 11- fied by the transformer 32,and that t ey are further amplified by the amplifier 39. It will befurther understood that the device will reproduce the music recorded ona phonograph record without the scratchin and other mechanical noisesincident to t e use of the usual sound box rep'roducer,-and that thetone and volume of the music may be varied at the will of the operatorthrough the medium of the adjustable grid resistance 52. A loud speakerespecially adapted for use in connection with this device is shown in mycopending application, filed 12th day of June, 1926, andseriallynumbered 115,523.

It should be understood that the drawings are merely illustrative and donot pretent to give exact proportions. Furthermore, the said drawingsare illustrative of a preferred construction, it being my expectationthat various changes and modifications may be made without departingfrom the spirit and scope of my invention.

What is claimed is r 1. An electrical reproducer embodying semi-circularpermanent magnets, pole pleces arranged-diametricall of the magnets andhaving their outer en s secured to a side of bein v of substantiallyU-form and arranged para lel to the plane. of the pole pieces andextending into the magnets, a coil located within the inner ends of thepole ieces, a frame extending through and beyon the coil and engaged bythe ends of the pole pieces to secure: it and the coil in place, and anarmatare arranged within and rockably supported by the frame.

2. An electrical reproducer embodyin a permanent magnet, pole piecesconnecte at their outer ends to the same side of the magnet and havinginner ends of substantially U form with their open sides facing eachother in a vertical plane, a coil located within the inner ends of thepole pieces, an open frame extending throu h and beyond the coil andengaged at points eyond the coil by the inner ends of the pole pieces tosecure it and the coil in place, and an armature arranged within androckably supported by the frame.

3. An electrical reproducerembodyin a permanent magnet, pole piecesconnecte to the magnet, a coil associated with the mag net, sides forthe coil, a hollow core passing through the coil and sides and providedwith In contacting with the outer faces of the si es, an open framesupported within the core, and an armature rockably supported within theframe.

In testimony whereof I afiix my signature.

I LELAND D. HARRIS.

the magnets, the inner ends of the pole pieces

